This invention relates to safety tool mounts for robotic apparatus, and more particularly to a device for mounting a tool, especially a welding torch, on the working arm of the apparatus, the device incorporating, for safety, means for deactivating the apparatus to prevent damage to the tool (or the apparatus) if the tool in the course of its movement by the apparatus should erroneously engage an impediment or obstruction to its movement thereby imposing deleterious force on the tool. The device may be referred to as a robotic deflection mount.
While the invention has been developed primarily for mounting a welding torch on the arm of robotic apparatus for robotic welding, it is to be understood that the mount of the invention may be readily adapted for mounting other tools for robotic operation, such as a cutting tool, an adhesive applicator, a grinding tool, etc.
Reference may be made to the following U.S. patents for examples of devices in the same general class as the present invention:
Among the several objects of the invention may be noted the provision of an improved safety mount for a tool such as a welding torch or other working instrumentality on robotic apparatus, the safety mount being improved to the extent of being more sensitive for deactivation of the robotic apparatus in the event the tool or instrumentality encounters an obstruction; the provision of such a safety mount which sensitively provides protection on angular or longitudinal deflection of the tool or instrumentality; the provision of such a safety mount which, while sensitive, provides protection in the event shutdown of the robotic apparatus for some reason should not occur immediately on occurrence of a deflection; and the provision of a safety mount having all the preceding attributes which is of such construction as to allow for acceptable tolerances in the manufacture thereof, which is readily installed on the robotic apparatus, and which is efficient and reliable in operation.
In general, in a first consideration thereof, the invention resides in a safety mount for a tool or other working instrumentality on robotic apparatus, for protection thereof should the tool or instrumentality encounter an obstruction to movement by the apparatus. The mount comprises a hollow housing having a first end and a second end and an axis extending longitudinally thereof passing through said ends, the housing being attachable at said first end to the robotic apparatus for robotic movement thereof. A plurality of electrical switches is mounted in the housing radially outward of said axis, each having an operating member facing toward said first end of the housing and biased toward said first end to a position establishing a first circuit condition and movable to a pressed-down position establishing a second circuit condition. A presser head for the switches in the housing biased in the direction toward said second end for pressing down the switch-operating members has a stem extending generally on said axis out of the second end of the housing for attachment thereto of a holder for said tool or instrumentality. The tool or instrumentality acts on encountering an obstruction either to deflect the stem at an angle to said axis with resultant angular deflection of the presser head releasing at least one switch-operating member or to move the stem inwardly with respect to the housing with resultant axial movement of the presser head away from the switch-operating members releasing all of them, thereby establishing said first circuit condition as a safety signal. In a second consideration, the invention encompasses a safety mount having a plurality of pairs of electrical terminals in the housing, each pair being situated radially outward of said axis, a member having a head in the housing and a stem extending generally on said axis out of the second end of the housing for attachment thereto of a holder for the tool or instrumentality. The member is biased in the direction toward said second end of the housing for effecting electrical connection of the terminals of each pair. The pairs of electrical terminals are connected in an electrical circuit in series for completion of the circuit when the terminals of each pair are connected. The circuit is broken when the tool or instrumentality encounters an obstruction with resultant angular deflection of the presser head breaking at least one of the connections or when the encounter moves the stem axially inward with resultant movement of the presser head to break all the connections.
Other objects and features will be in part apparent and in part pointed out hereinafter.